a group of aquatic plants that contain chlorophyll and other pigments that allow them to photosynthesise. Many algae are single-celled and can grow into large colonies. Others are large plants, such as seaweeds
Algal bloom
rapid growth of algae caused by lots of nutrients in the water and the right conditions for growth. An algal bloom can deoxygenate the water and kill animals and other plants
Angiosperms
flowering plants are called 'angiosperms', from Greek, meaning 'container for male reproductive cells'
Aquaculture
farming fresh or saltwater fish, molluscs, crustaceans or plants
Aquatic
anything to do with water
Antifouling paint
paint that is put on the hulls of boats to stop them being 'fouled' by barnacles and other animals and plants attaching themselves to the hull
Benthic
bottom-dwelling
Biota
living things
Blue-greens
also called 'cyanobacteria', these bacteria can photosynthesise. Some also make toxins
Brackish
slightly salty water
Catchment
the surface of land that collects rain which then flows into a waterway
Chlorophyll 'a'
a measure of the amount of green pigment (chlorophyll) in water. This green colour is the photosynthetic material in microscopic algae called phytoplankton. High levels indicate that there are large growths of phytoplankton, fed by an excess of nutrients available in the water and/or the sediments. Chlorophyll `a' is commonly used to measure eutrophication
Deoxygenation
this occurs when there isn't enough oxygen in the water, for example because an algal bloom uses it all up or because the water is full of silt. Fish can die of asphyxiation and plants may die through lack of nutrients
Detritus
leaves and other plant and animal matter that other living things feed on
Diatoms
single-celled algae
Diffuse source pollution
pollution that comes from a lot of different places, such as stormwater or agricultural run off
Dinoflagellate
a single-celled planktonic animal that produces toxins which can kill fish and cause severe illness or death in humans
Discharge
an outflow of water
Ecosystem
all of the interactions between plants, animals, earth, water, fire and air in a specific environment
Effluent
liquids, solids or gases discharged as waste
Entrance bar
sand or silt across the entrance to an estuary from the sea
Estuary
an enclosed or semi-enclosed coastal waterbody which is open permanently or temporarily to the sea and into which fresh water flows from rivers or creeks from the land
Eutrophication
(from Greek, meaning 'well-fed') too many chemicals in the water that plants use for growth can lead to an over-abundance of plants, particularly algae. The basic classes of eutropy (another word for eutrophication) are oligotrophic, mesotrophic and eutrophic. Oligotrophic (from the Greek 'oligos', meaning 'few') waterbodies don't have much growing in them at all. There is not much algae and the water is very clear. Eutrophic systems have a lot of aglal blooms. Mesotrophic systems are between the other two
Evaporation
water being turned into water vapour by the sun
Faeces
solid animal or human waste from the intestines
Fauna
animals
Fisher
person who catches fish
Floc
a tuft-like mass (from Latin 'floccus', meaning 'flock of wool')
Floodplain
the low ground around a river that is flooded
Flood mitigation works
constructions or earthworks designed to reduce the damage caused by floods
Flora
plants
Food web
the way animals and plants live off each other
Fringing vegetation
trees and other plants that grow along the edges of a waterway
Groundwater
water underneath the ground in its pores and crevices
Groundwater mound
sometimes groundwater forms a shape like a mound. The top of the mound can be higher than sea level
Gilvin
the dissolved organic carbons which colour water brown (i.e. absorb light in the 400-440 nm wavelength). There are many chemicals which make up gilvin and tannin is just one of these
the continual movement of water between the land, sea and air
Integrated Catchment Management (ICM)
coordinated planning, management and use of water, land, plants and other natural resources in a catchment by community groups and government agencies working together
Intertidal
the area of land that's covered by water at high tide and exposed at low tide
Invertebrates
animals without spines or backbones
Larvae
an animal's young that then transforms; the young of any invertebrate
Leachate
water carrying impurities that has percolated through the earth
Levee
a bank or wall built to keep floodwaters away; or a bank that occurs naturally because of silt being deposited during floods
Littoral
the shore of a lake, sea or ocean
Macroalgae
algae which can be seen easily, without using a microscope. Includes large seaweeds
Macroinvertebrates
animals without backbones which are big enough to be seen without a microscope. These include worms, snails, prawns and insects
Microalgae
algae which can only be seen with a microscope
Microcatchments
small catchments such as parks, roadways, backyards
Nitrogen-fixing
the process by which some plants (e.g. legumes) and micro-organisms (e.g. bacteria) extract nitrogen from the atmosphere
Nutrients
chemicals that plants and animals use to grow
Outfall
a drain or pipe
Organic
something that is, or was, living
Organism
a living thing
Pathogens
living things such as viruses and bacteria which cause illnesses
pH
a measure of acidity. It is defined as the negative logarithm of the effective hydrogen (H) ion concentration in moles per litre. Pure water has a pH of 7. Acid solutions have lower pH and alkaline solutions have higher pH.
Photosynthesis
the process green plants use to grow by using sunlight, water and chemicals
Plankton
small organisms which move or drift in water. The plants are called `phytoplankton' (`phyto' means `plant' in Greek), the animals are called `zooplankton' (`zoo' is from Greek, meaning `animal')
Point source pollution
pollution that comes from one point, such as a sewerage or factory outfall
Predatory
hunting and killing others
Primary consumers
animals which feed directly on plants or detritus
Primary producer
a green plant
Pseudo-faeces
waste from creatures that don't have intestines
Pupal stage
the stage of growth of a creature where they are inside a pupa or `cocoon'
Pressures
in this book, things that can cause harm to animal or plant populations are called `pressures'
Ross River fever or virus
an illness carried by mosquitoes. It causes symptoms like severe flu and can last for a long time
Runoff
water that flows along the ground after rain and ends up in streams, reservoirs or the ground
Salinisation
increased saltiness in soil or water
Salinity
how much salt there is in water
Salt tolerant
plants or animals that can live in salty land or water
Salt wedge
In an estuary or tidal river in summer, when the river flow is less, the salty sea water can move upstream under the fresh river water (because the salt water is heavier and denser). This process of layering of fresh water over sea water is called a salt wedge
Secchi disc
a black and white disc used to measure turbidity
Sediment
sand, clay, silt, pebbles and organic material carried and deposited by wind or water
Sedimentation
the process of sediment being deposited, such as on the bed of a river or estuary
Sediment load
the amount of sediment carried in a stream
Sewage
the waste that goes through sewers
Sewerage
the system of pipes that carries sewage
Siltation
fine particles of sand, mud and other things picked up by water and deposited to form sediment
Species
scientists have divided animals and plants into different categories, starting with 'kingdoms' (the plant kingdom and the animal kingdom), then 'families', through 'genera' to 'species' and 'variations'. An animal that is the same species as another animal will have a lot in common. All living things are being given scientific names. For example, green lip abalone's scientific name is Haliotis laevigata, and brown lip abalone's is Haliotis conicopora. The word Haliotis is the genus name and the next word is the species name. So the two abalones are similar but not the same. Scientific names are always in italics
Stormwater
rainwater which has run off roads, the ground, roofs, footpaths etc and is usually carried away by drains
Stratification
fresh water lying on top of of salt water
Subcatchments
catchments, around tributaries, that together make up the bigger catchment of the main river or waterbody
Sub-polar
just below the north or south Poles (places that are very cold)
Surface water
water flowing in streams or held in reservoirs such as dams and wetlands
Suspended solids
tiny bits of soil, plants and animals floating in water
Sustainable development
development that meets the needs of the present without destroying things for future generations
Tannin
a group of chemicals found in different plants that gives a particular colour and taste to them or water they might be in (see Gilvin). Used to 'tan' leather
Terrestrial
of the land
Tidal range
the difference in height and depth between the low and high tides
Topsoil
the top part of the soil
Toxic
poisonous
Toxicity
how poisonous something is
Toxins
poisons
Transpiration
plants give off water vapour at night. It's called `transpiration'
Tributary
A stream, creek or river that flows into a larger stream or lake
Turbidity
Muddiness of water cause by suspended solids such as soil and bits of plants
